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Demand Estimate
Water UseAverage Flow (GPD/Capita)
# of People
ADD (GPD)
MDD^(ADD*2.4)
PHD^(MDD*1.85)
Residential 100 10,000 1,000,000 2,400,000 4,440,000Commercial/Retail 25 1,500 37,500 90,000 166,500
TOTAL Gal/d 1,037,500 2,490,000 4,606,500
TOTAL MGD 1.04 2.49 4.6065
Assuming that there are an average of 4 people per house, then a total of 2,500 service connections will be required.
^TCEQ RG-195.
Service Level Measures
Surface Water Supply System
0.6 gpm/unit Raw water pump capacity with largest pump out of service
0.6 gpm/unit Treatment plant capacity
200 gal/unit TOTAL Storage Capacity
100 gal/unit Elevated Storage Capacity
10 gal/unit Pressure Tank Storage Capacity
35 gal/unit Ground Storage
TCEQ 290.45
Service Level Measures
Ground Water Supply System
1.0 gpm/unit Well capacity; <100 units w/o ground storage
0.6 gpm/unit Well Capacity; <100 units with ground storage
• Well capacity which meets or exceeds the MDD
• Ground storage capacity equal to 50% of the MDD
• At least two service pumps with total capacity of 3X the MDD
• Minimum pressure tank capacity of 220 gallons
TCEQ 290.45
Service Level Measures
TCEQ 290.44
Pressure (PSI)
Flowrate (GPM/connection)
Minimum 35 (normal)20 (fire flows)
1.5
Maximum 80 -
Alternative Methods of Service• Alternative 1: Drill a new water well to be operated by CS
utilities• Water will be treated at existing treatment facilities, and
citizens will purchase water from CS• Alternative 2: Drill a new water well and treat the water at
new treatment facilities• Alternative 3:Use surface water and construct a treatment plant • Alternative 4: Shared water wells located in the development
Infrastructure RequiredItem TypeStorage Tank Elevated
Water Well 100 GPM
Pipes 6” PVC, 18” and 24” concrete
Pumps/Stations Booster, 1500 GPM centrifugal
Valves Isolation, 6” and 18”
Hydrants
Treatment Plant 2.5 MGD (Option 2)
Estimate of Facilities and Cost – Option 1 Capital Costs
Item Description Quantity Unit Cost Total Cost1000 GPM water wells 2 1,000,000 2,000,000 [1]site work 1 100,000 100,000 [1]
Piping Booster pump station 2 37,000 74,000 [1]6" PVC 64,000 50 3,200,000 [2]18" Concrete 9,500 200 1,900,000 [3]Piping to Community (24" Concrete) 52,800 200 10,560,000 [3]
Valves Booster pump station 2 13,000 26,000 [1]6" valves 2,500 1,000 2,500,000 [4]18" valves 80 4,800 384,000 [5].75 MG EST 1 2,000,000 2,000,000 [6]
Pumps Add to Sandy Point Pump Station 4 30,000 120,000 [7]Booster Pump Sta on site – 1500G GPM Centrifugal Pumps 4 30,000 120,000 [7]Booster Pump Building 1 85,000 85,000 [1]electrical and controls 1 138,000 138,000 [1]
Hydrants 500 2,350 1,175,000 [5]TOTAL$24,382,000
Estimate of Facilities and Cost – Option 2 Capital Costs
Item Description Quantity Unit Cost Total Cost1000 GPM Water well 2 1,000,000 2,000,000 [1]
Site work 1 100,000 100,000 [1]Piping Booster pump sta 2 37,000 74,000 [1]
6" PVC 64,000 50 3,200,000 [2]18" Concrete 9,500 200 1,900,000 [3]
Piping to Community (24" Concrete) 158,400 200 31,680,000 [3]Valves Booster pump sta 2 13,000 26,000 [1]
6" valves 2,500 1,000 2,500,000 [4]18" valves 80 4,800 384,000 [5]
.75 MG EST 1 2,000,000 2,000,000 [6]Pumps Booster Pump Sta on site 4 30,000 120,000 [7]
Booster Pump Sta by well 4 30,000 120,000 [7]Booster Pump Building 2 85,000 170,000 [1]electrical and controls 1 138,000 138,000 [1]
Hydrants 500 2,350 1,175,000 [5]TOTAL$45,587,000
Summary
• Option 1 was selected as providing the lowest cost.• Recommendation: Drill a new water well to be operated by
CS utilities• Water will be treated at the existing treatment facilities,
and citizens will purchase water from CS
Option TotalPer New
HouseholdPer Capita in
College Station
1 $31.7 M $12,700 $300
2 $59.3 M $23,700 $560
Questions?
AcknowledgementsThank you to Dr. Stockton for taking the time to join our class, and for teaching us about Public Works